Generally, the door hinge is ordinary hinge, and the method by which the door slowly closes is to provide door closers on the door. But the structure of the door closers is complex, and is not conducive to the beautiful appearance. Thus, a slow-closing door hinge with simple structure and connecting with the hinge together is desired.
Chinese application No: CNO2243797.5 discloses a slow-closing door hinge, which includes a hinge consisting of an active foldout, a fixed foldout and a shaft. A hydraulic damping device is provided in the door or the door frame and a connecting transmission device for connecting the foldout and the hydraulic damping device. The hydraulic damping device of the slow-closing door hinge plays a buffer role during the door and window being opening or closing. The problem that there is no he hydraulic damping device in the existed hinge, and adding the hydraulic damping device to affect the appearance of the window and door and so on, is solved. But the above structure is larger.
The connecting of the connecting rod relatively fragile, easily damaged. And the production and installation is more trouble.
Chinese patent application No: CN200710146296.8 discloses a slow-closing door hinge, which includes two foldouts with shaft sleeve and a linkage mechanism within the shaft sleeve which are correspond to one of shaft sleeve respectively. Two shaft sleeve correspondingly are interlocked up and down via the linkage mechanism. The linkage mechanism includes a linkage buffer mechanism for preventing door and window from being closed too fast. The linkage buffer mechanism consists of a shaft body, a lifting rod which is on one end of the shaft body and can move up and down relative to the shaft body along the axial direction, and a buffer for buffering the lifting rod moving up and down to buffer the relative rotation of the lifting rod. Among them, the shaft body and a shaft sleeve are relatively fixed and rotate together in a coaxial, By the clamping connection between the lifting rod and the shaft sleeve of another hinge, the lifting rod can lift up and down, when the lifting rod and the hinge fixedly rotate. Compared to the previous slow-closing door hinge, the structure of the slow-closing door hinge is relatively simple, and the size is small. But the structure of the buffer mechanism with multi elements is still more complex, and is not conducive to the installation. And the structure of some foreign the slow-closing door hinge is more complex, and prone to failure in use, thus buffer function disappears.